PEMFC System Research Articles

Cathodic Supply Optimization of PEMFC System Under Variable Altitude

Cathodic Supply Optimization of PEMFC System Under Variable Altitude

Potential Evaluation of Twin-Screw Air Expanders with Dual-Lead Rotors Used in PEMFC Systems

The reduction in the power cost of air supply systems has emerged as a critical challenge in the development of polymer electrolyte membrane fuel cells. This study proposes the use of dual-lead rotors to improve the performance of twin-screw expanders for the purpose of boosting expanders’ recovery power and consequently lowering the power cost of the air supply subsystem, which is hardly investigated in previous publications. For this purpose, a mathematical model is built to assess the potential of improving the expander performance by means of the dual-lead rotors. And the influence of lead and length of the high-pressure rotor segment and overall rotor length are analyzed. The results demonstrate that the smaller lead and larger length of the high-pressure rotor segment result in better geometric characteristics and thus thermodynamic performance. For example, case #4 with dual-lead rotors exhibits a larger rotating angle at the suction end and a larger suction area than those of constant-lead rotors by 43° and 100%, respectively, which further lower the suction pressure loss. Compared with constant-lead rotors, the maximum increments in the mass flowrate and indicated power are observed as 45% and 25.4%, respectively. However, the dual-lead rotors could not effectively contribute to an increase in the isentropic indicated efficiency of twin-screw expanders due to the severe leakage, and hence, it becomes crucial to address the leakage issues in twin-screw expanders.

Numerical studies on structure optimization and flow characteristics of a hydrogen recirculation ejector under multiple load conditions

Ejectors are ideal hydrogen recirculation devices for PEMFC systems but typically exhibit poor recirculation performance at low loads. For purpose of extending ejector's operating range in vehicular applications, the entraining performance across multiple loads should be focused. In this study, A 40 kW ejector was designed with a 1D theory and optimized using a 2D CFD model. Simulations were conducted to study the influence of various diameter and axial dimensions on the ejector's performance and flow characteristics. The results reveal that as the load increases from 20% to 100%, the suboptimal diffuser exit diameter decreases from 2.5 to 1.5 times the mixing chamber diameter, the optimal nozzle exit position increases from 0.59 to 0.63 times, and the optimal mixing chamber length increases from 2.2 to 4.3 times. A convergent nozzle with a short throat significantly improves low-load entraining performance and achieves the highest performance growth in the variable-nozzle design. Additionally, an optimization method for axial dimensions based on the proposed parameter flow uniformity was established, allowing for precise determination of the optimal dimensions through a few simulations.

Dynamic Performance Analysis of A Turbocharged Pemfc System

Dynamic Performance Analysis of A Turbocharged Pemfc System

Disturbance Observer-Based-Model-Free Adaptive Fuzzy Fractional-Order Prescribed Performance Control for Nonlinear PEMFC System with Uncertainties and Performance Constraints

Disturbance Observer-Based-Model-Free Adaptive Fuzzy Fractional-Order Prescribed Performance Control for Nonlinear PEMFC System with Uncertainties and Performance Constraints

A fuel cell powered rack prototype for data center application with waste heat recovery: design consideration and experimental verification

The combination of data center and PEMFC has been a promising data center zero-carbon emission solution. However, the relevant experimental studies are very rare and most work only solved the simple electrical coupling. This paper proposed a new in-rack data center servers and PEMFC coupling design scheme considering both the electrical coupling and thermal management coupling of the servers and PEMFC, and built a cabinet prototype for the first time. The complete multi-condition continuous experiment on the PEMFC system fully demonstrates the servers power supply stability of the prototype with the fast tested power response capability of 4.9 kW in 0.1 s. The experiments under rated condition (when the servers power is 5 kW) were conducted and the carbon emission level and efficiency performance of the prototype are analyzed. Under the rated condition, the highest prototype CHP efficiency is 64.1 % while the prototype can provide 41.6 ℃ hot water with 3.04 L·min-1 and the lowest prototype CHP efficiency is 59.8 % while the prototype can provide 61.1 ℃ hot water with 1.33 L·min-1. The prototype maintains the zero-carbon (or negative carbon) emission of servers. The average operation carbon emission rate is -35 g·h-1. Compared with the full grid supporting data center, the power average prototype operation carbon reduction rate is 0.13 g·s-1·kW-1. The application potential of the proposed data center and PEMFC coupling scheme is demonstrated with the prototype experiment results from the advantage of carbon emission and heat recovery potential.

Model Guided Extremum Seeking and Active Disturbance Rejection Control for Efficiency Real-Time Optimization of PEMFC System

Model Guided Extremum Seeking and Active Disturbance Rejection Control for Efficiency Real-Time Optimization of PEMFC System

Innovative Design of Solid-State Hydrogen Storage and Proton Exchange Membrane Fuel Cell Coupling System with Enhanced Cold Start Control Strategy

This paper presents an innovative thermally coupled system architecture with a parallel coolant-heated metal hydride tank (MHT) designed to satisfy the hydrogen supply requirements of proton exchange membrane fuel cell s(PEMFCs). This design solves a problem by revolutionising the cold start capability of PEMFCs at low temperatures. During the design process, LaNi5 was selected as the hydrogen storage material, with thermodynamic and kinetic properties matching the PEMFC operating conditions. Afterwards, the MHT and thermal management subsystem were customised to integrate with the 70 kW PEMFC system to ensure optimal performance. Given the limitations of conventional high-pressure gaseous hydrogen storage for cold starting, this paper provides insights into the challenges faced by the PEMFC-MH system and proposes an innovative cold start methodology that combines internal self-heating and externally assisted preheating techniques, aiming to optimise cold start time, energy consumption, and hydrogen utilisation. The results show that the PEMFC-MH system utilises the heat generated during hydrogen absorption by the MHT to preheat the PEMFC stack, and the cold start time is only 101 s, which is 59.3% shorter compared to that of the conventional method. Meanwhile, the cold start energy consumption is reduced by 62.4%, achieving a significant improvement in energy efficiency. In conclusion, this paper presents a PEMFC-MH system design that achieves significant progress in terms of time saving, energy consumption, and hydrogen utilisation.

Global warming potential and societal-governmental impacts of the hydrogen ecosystem in the transportation sector

The environmental and societal challenges of our contemporary society are leading us to reconsider our approaches to vehicle design. The aim of this article is to provide the reader with the essential knowledge needed to responsibly design a vehicle equipped with a hydrogen fuel cell system.Two pivotal aspects of hydrogen-electric powertrain eco-design are examined. First, the global warming potential is assessed for both PEMFC systems and Type IV hydrogen tanks, accounting for material extraction, production, and end-of-life considerations. The usage phase was omitted from the study in order to facilitate data adaptation for each type of use. PEMFC exhibits a global warming potential of about 29.2 kgCO2eq/kW, while the tank records 12.4 kgCO2eq/kWh, with transportation factors considered. Secondly, the societal and governmental impacts are scrutinized, with the carbon-intensive hydrogen tank emerging as having the most significant societal and governmental risks. In fact, on a scale of 1–5, with 5 representing the highest level of risk, the PEMFC system has a societal impact and governance risk of 2.98. The Type IV tank has a societal impact and governance risk of 3.31.Although uncertainties persist regarding the results presented in this study, the values obtained provide an overview of the societal and governmental impacts of the hydrogen ecosystem in the transportation sector. The next step will be to compare, for the same usage, which solution between hydrogen-electric and 100% battery is more respectful of humans and the environment.

Optimization of PEMFC pressure control using fractional PI/D controller with non-integer order: design and experimental evaluation

The fuel-based proton exchange membrane (PEM) fuel cell is a promising technology for clean energy production owing to the several advantages including high efficiency (around 80% theoretical), quiet in operation, and almost zero emission as compared to conventional internal combustion engine. Only hydrogen and oxygen are supplied at the anode and cathode, respectively to generate power and water is produced as by product. However, it suffers to achieve its maximum theoretical efficiency due to lack of flow/pressure management of hydrogen and oxygen in the PEMFC stack which also causes flooding within the cell and reduce the performance of the catalyst and reduces the efficiency. The higher efficiency can be achieved with the proper control of the hydrogen and oxygen inlet flow rate and pressure at the PEMFC. Since it’s crucial to maintaining a consistent supply of exponential pressure, the main focus of this work is pressure regulation at the PEMFC cathode side. A fractional PI/D controller is designed to operate the PEMFC system more realistically. There are three primary objectives of this research work. In the first step, monitoring the PEMFC operating pressure to find out the suitable fractional PI-D controller for a given resilience level, which has the lowest Integration Absolute Error (IAE) to disturbances. The robustness level and/or threshold peak is considered as a tuning parameter for the evaluation. Second, compare the best IAE performance of the fractional PI-D controller with that of simple SIMC rules, where a certain level of resilience is achieved by varying the SIMC tuning variable. Through this comparison, the effectiveness of the recommended controller in achieving the optimal plant performance is evaluated. Thirdly, design a non-integer order PEMFC plant with a fractional controller using MATLAB software and compare the results with existing models. This comparison provides insight into the practical performance of the proposed controller. The results shows that the developed fractional PI/D controller is able to control the pressure very efficiently at the PEMFC cathode side. The findings further emphasise on the important to consider the resilience and robustness levels at the time of developing control systems for PEMFCs. The efficacy of the suggested unique technique is further confirmed by contrasting the suggested controller with the developed models.

Pressurization process and performance analysis of gear-claw hydrogen circulating pump used in PEMFC system

Pressurization process and performance analysis of gear-claw hydrogen circulating pump used in PEMFC system

Health Management for PEMFC System Long-Term Operation Based on Optimal Temperature Trajectory Real-Time Optimization

Health Management for PEMFC System Long-Term Operation Based on Optimal Temperature Trajectory Real-Time Optimization

Multivariable Cooperative Control for Performance Guarantee of PEMFC System in High-Altitude Environment

Multivariable Cooperative Control for Performance Guarantee of PEMFC System in High-Altitude Environment

Exergy, economic, exergoeconomic and environmental (4E) analyses and multi-objective optimization of a PEMFC system for coalbed methane recovery

Exergy, economic, exergoeconomic and environmental (4E) analyses and multi-objective optimization of a PEMFC system for coalbed methane recovery

Optimum Load Of a Proton Exchange Membrane Fuel Cells Based on Hydrogen Flow Control

In the future, proton exchange membrane fuel cells system (PEMFCs) hold promises for clean energy. However, there is a problem that causes the degradation in PEMFC system performance namely the voltage drops due to load fluctuations. The voltage drop is caused by the high load power demand. An important factor to improving PEMFCs performance is the availability of sufficient flow of hydrogen. In this paper optimisation of a PEMFCs load based on the hydrogen flow control is presented. In order to validate this project a model of the PEMFCs is simulated. Then verified by experimental testing using a 2 kW of the PEMFCs. The result shows the hydrogen flow control able to reduce the voltage drop of the PEMFCs during load variation and minimise hydrogen consumption.

Challenges and optimization of PEMFC system in vehicles

Switching from fossil fuel energy to clean and renewable energy to minimize car emissions is becoming more and more vital and crucial in the current condition of severe environmental pollution and serious fossil fuel shortage. However, there are still several issues with current fuel cell systems that prevent their widespread use. Due to Proton Exchange Membrane Fuel Cells’ (PEMFCs) poor performance and the expensive operating costs of their catalysts, fuel cells are presently not widely accessible on the market. Fuel cells are seen as a potential method to reach the goal of zero emissions since they offer excellent benefits in terms of zero emissions and high efficiency. They do this by converting chemical energy into electrical energy using hydrogen. In this study, the three main parameters that affect the performance of PMFCs and the way in which the fuel cell converts chemical energy into electrical energy are investigated. Carbon corrosion damages PEMFCs performance because of high cathode potential during startup and shutdown. The breakdown of platinum particles employed as catalysts reduces the lifetime of PEMFCs and raises costs. The improvement of fuel cell systems is reviewed, along with methods for gas purification and catalysts produced from various cutting-edge materials including graphitized carbon. In order to address any potential environmental issues with fuel cells and seek to lower greenhouse gas emissions, this paper intends to explore better alternatives and give better remedies for PEMFC performance improvement and cost reduction.

Використання термоакустичних технологій в суднових гібридних енергетичних установках з паливними комірками

Recently, hybrid power plants have gained significant popularity in marine energy systems. These power plants, in addition to traditional thermal engines, include electrochemical power generation systems based on fuel cells. Hybrid marine power plants represent a relatively new technical solution for the maritime fleet, driven by strict environmental emission regulations imposed by international organizations. These regulations primarily target greenhouse gas (GHG) emissions, such as carbon oxides, methane, nitrogen oxides, and other compounds. An analysis of the current state of marine energy and its development trends concludes that the problem lies in the working processes of thermal engines, which are based on fuel combustion. Achieving ecological cleanliness in maritime transport is possible by transitioning to new principles of mechanical energy production that do not rely on chemical fuel combustion. Fuel cells, which generate electricity through electrochemical processes, have the potential to solve this problem. However, the implementation of such electrochemical generators requires a systematic approach to the development of schematic solutions capable of achieving a synergistic effect. The subject of the research is the regularities and parameters of energy exchange processes in hybrid power plants. This study focuses on hybrid power plants with electrochemical generators based on proton exchange membrane fuel cells (PEM FC). The effective operation of hybrid power plants involves the utilization of waste heat from ship equipment. PEM FC is the most widely used type of fuel cell in energy and transportation sectors. The operating temperatures of PEM FCs, depending on their type, range from 60 to 80°C or 120 to 200°C, which poses a challenge for the development of efficient waste heat utilization systems. The aim of the research is to develop waste heat utilization schemes for hybrid power plants with PEM FCs using thermoacoustic heat engines. The study establishes that electrochemical generators can be integrated into the thermal system of modern power plants, and the application of thermoacoustic heat engines expands the potential of waste heat utilization systems. Low-temperature thermoacoustic engines have the capability to convert waste heat generated by PEM FC systems into mechanical work, thereby increasing the overall efficiency of hybrid power plants by 8 to 15%.

Morphology effect of Pd/In2O3/CeO2 catalysts on methanol steam reforming for hydrogen production

Catalyst support morphology strongly influences its surface and structural properties, therefore, may have a significant impact on their reactivity in heterogeneous catalysis. Herein, the Pd/In2O3/CeO2-x (loaded with 1 wt% Pd and In2O3) catalysts with different morphologies of rods(r), cubes(c) and irregularity(w) shapes were prepared by hydrothermal method and impregnation method. At temperature of 275–425 °C, as-prepared catalysts were evaluated for hydrogen production from methanol steam reforming (MSR). The activity data showed the outstanding performance of the rod-shaped Pd/In2O3/CeO2 catalysts, exhibiting the complete conversion of methanol and particularly low CO (1.3%) at 375 °C. The structural properties and physicochemical of Pd/In2O3/CeO2-x with different morphologies were characterized by means of X-ray diffraction (XRD), high resolution transmission microscopy (HR-TEM), CO pulse chemisorption, X-ray photoelectron spectroscopy (XPS) and temperature programmed desorption of methanol (CH3OH-TPD). Activity data and catalyst characterization results correlated, and indicated that the excellent reactivity for the rod-shaped Pd/In2O3/CeO2 catalysts in MSR is ascribed to the large particle size of palladium nanoparticles and the abundant oxygen vacancies induced by the strong interaction between Pd, In and Ce. HR-TEM results revealed that rod-like CeO2 mainly expose (110) crystalline surface with high mobility of surface oxygen and possess the most abundant surface oxygen vacancies with the low formation energy, facilitating the formation of active species of Pd0 on catalyst surface, and promoting the activation and adsorption of methanol and water molecules. Furthermore, the rod-shaped Pd/In2O3/CeO2 catalysts showed excellent reactivity and stability in MSR for 30 h, demonstrating its potential of being used as catalysts in methanol steam reforming in PEMFC systems.

CFD investigation of a fast-response humidifier for high-power PEMFC test stations

Unlike operating PEMFC systems with internal humidification from hydrogen recirculation, fuel cell stack test stations mainly rely on external humidification. Response time in the order of 10s and power over 100 kW are crucial requirements for test stations for vehicle fuel cell stacks. In the present study, a 3D computational fluid dynamics (CFD) model of a swirl spray humidifier is developed to simulate the conjugated heat and mass transfer in such a humidifier. In the model, hot, dry air enters from the bottom portion of the humidifier tangentially and mixes with liquid droplets from a nozzle placed near the middle. A discrete phase model (DPM) is employed to model the atomized droplets. Time variations of the flow structure and humidity distribution are studied. A parametric study with the nozzle parameters on humidifier performance is carried out, showing that optimal humidifier performance can be obtained with a single nozzle and spray temperature at 300 K. The humidity response at the humidifier exit subject to a load change is investigated. The simulation results show that the humidifier's dynamic response time for the baseline case is about 32s, with a steady relative humidity of 95.25% and an evaporation rate of 98.4% at the exit. The present model can guide the future design of fast-response, high-power humidifiers for fuel cell stack test stations.

Design and analysis of a hybrid space heating system based on HT-PEM fuel cell and an air source heat pump with a novel heat recovery strategy

This work analyzes the performance of a system integrating high temperature proton exchange membrane fuel cell (HT-PEMFC) and air source heat pump (ASHP) technologies for residential space heating. The main goal is to improve energy conversion efficiency for a residential building in the Canadian climate, in which methane is normally used to feed traditional systems (e.g., boilers and/or furnaces), due to its considerable local availability. On the other hand, ASHP technology is characterized by high efficiency, but normally fails to perform well in cold climates, due to the reduction of the coefficient of performance (COP) and ice formation on the evaporator. Due to the higher attention paid to low temperature PEMFC system (LT-PEMFCS) till now, it is here investigated if significant improvements can be obtained with a higher temperature PEMFCS, by thus fully exploiting the higher quantity and better quality of recoverable waste heat compared to LT-PEMFCSs, particularly aiming at mitigating the afore-mentioned low-temperature related issues. A mathematical model for the system components is proposed to perform parametric analyses aimed at assessing the variation of efficiency as a function of both environmental and load conditions. The results show that the ASHP COP increases by more than 77% when the HT-PEMFCS works at its nominal (5.3 kW) power and/or inlet air has a high relative humidity (RH), i.e., close to 100%. The proposed HT-PEMFC system configuration was able to reach a total COP higher than 1.5, leading to a reduction of the needed primary energy needed and a consequent reduction of the operating costs by up to 60% compared to boilers.